Schrotz



Oct. 31, 1961 K. SCHROTZ 3,006,036

TEXTILE DRAWING MECHANISM Filed Oct. 15, 1958 s Sheets-Sheet 1 INVE/VTOR Oct. 31, 1961 K. SCHROTZ TEXTILE DRAWING MECHANISM Filed Oct. 15, 1958 3 Sheets-Sheet 2 Oct. 31, 1961 K. SCHROTZ TEXTILE DRAWING MECHANISM 5 Sheets-Sheet 5 Filed Oct. 13, 1958 U I N EM V S N w k United States Patent 3,006,036 TEXTILE DRAWING MECHANISM Kurt Schrotz, Fellbach, Baden-Wurttemberg, Germany, assignor to SKF Kugellagerfabriken Gesellschaft mit beschrinkter Haftung, Schweinfurt, Germany, a company of Germany Filed Oct. 13, 1958, Ser. No. 766,974 Claims priority, application Germany Oct. 24, 1957 Claims. (Cl. 19-135) This invention relates to drawing mechanisms for textile machinery and, more particularly, is directed to improvements in devices for releasably locking the top roll carrying and weighting arms of such drawing mechanisms in their working or operative position.

In drawing mechanisms for textile spinning frames and the like, weighted twin top rolls cooperate with lower rolls which are rotatably supported in an under frame of the mechanism. The twin top rolls are individually suspended from a pivoted carrier arm which is movable between a lowered operative or working position and a raised inoperative position, and springs act between the pivoted carrier arm and the top rolls suspended therefrom to urge the latter toward the related lower rolls with respect to the pivoted carrier arm in the operative position of the latter. It is apparent that such springs acting between the pivoted carrier arm and the individually suspended twin top rolls will be effective to weight the latter, or to press them against the related lower rolls, only so long as the pivoted arm is locked or retained in its operative position against the reactions to the forces of the springs against the top rolls.

Although devices have been provided for releasably retaining the pivoted carrier arm in its operative position, such existing devices are usually complex in construction and unreliable or time-consuming in operation. Thus, by way of example, one existing device for releasably retaining the pivoted carrier arm in its operative position includes a plurality of cooperating detent members mounted in the carrier arm and loaded by springs acting in opposition to each other, with one of the detent members being in the form of a hook adapted to cooperate with a complementary member mounted in a stationary part of the drawing mechanism for holding the carrier arm in its operative position. Apart from the expense and unreliability of operation resulting from the comparatively large number of parts included in the above existing device, the latter has the further disadvantage that, after the carrier arm has been unlocked or released, it can only be relocked in its operative position following the upward swinging of the arm to its inoperative position and then the downward swinging of the arm back to its operative position. Such upward and downward swinging of the carrier arm prior to the relocking of the latter in its operative position, is a time-consuming procedure, particularly when a great number of drawing mechanisms are provided on the associated textile machinery and must all be relocked prior to resuming operation of the latter.

Since it is necessary that the weighting of the top rolls of all the drawing mechanisms on a textile machine should be relieved during any prolonged stoppage in the operation of the textile machine, in order to avoid permanent deformation of the resilient covers of the top rolls which would lead to the production of faulty yarn during the subsequent operation of the machine, it is obvious that the rapid relocking of the carrier arms of the drawing mechanisms in their operative positions is a desirable objective.

Accordingly, it is an object of the present invention to overcome the above mentioned disadvantages of the existing locking devices in drawing mechanisms, and particu- "ice larly, to provide a drawing mechanism with a locking device for the pivoted carrier arm thereof which permits the reliable, rapid and easy locking and unlocking of the carrier arm in its operative position, and which is of simple construction embodying a relatively small number of elements or parts.

A further object is to provide a locking device for the pivoted carrier arm of a drawing mechanism, in which the carrier arm can be relocked in its operative position immediately after its release, and without requiring the swinging of the arm to and from its inoperative position, as in the existing devices described above.

In accordance with an aspect of this invention, a drawing mechanism has the usual fixed support and an arm pivoted on that support and suitably carrying the top rolls, with the pivoted carrier arm being swingable between a depressed operative or working position, in which the top rolls are resiliently weighted or pressed against the related bottom rolls, and a raised inoperative position, and the drawing mechanism is provided with a locking device for releasably retaining the carrier arm in its operative position, such locking device including a pivoted latch mounted on the stationary support and resiliently urged to a position where the latch comes into locking engagement with hook-shaped extensions of the carrier arm when the latter is disposed in its operative position, the latch being movable out of locking engagement with the hook-shaped extensions of the carrier arm in response to the displacement, relative to the carrier arm, of an operating member which is preferably in the form of a hood extending over the carrier arm.

In order to reduce the frictional resistance to the engagement and release of the locking device embodying the invention, the latch thereof preferably has rollers for engagement with the hook-shaped extensions or latch hooks of the carrier arm, and such rollers, upon actuation of the operating member, are moved out of their locking positions, where they are in full engagement with the latch hooks, and assume positions where they can be immediately re-engaged with the latch hooks or, alternatively, the carrier arm can be raised to its inoperative position.

In accordance with another aspect of the invention, the latch hooks on the carrier arm, and the pivoted latch are mutually arranged so that, following the actuation of the operating member, the resilient force acting upon the latch is transmitted by way of the latter and the latch hooks to the carrier arm to lightly urge the latter toward the bottom rolls, and the individual mountings of the twin top rolls in the carrier arm are adjusted so that the foremost twin top rolls can rest on the related bottom rolls, while the remainder of the top rolls are raised from the related bottom rolls. With this arrangement, the yarn continues to be gently gripped between the foremost top and bottom rolls when the carrier arm is unlocked during stoppage of the associated textile machine so that the twist of the yarn cannot extend into the drawing field, but this comparatively light pressure acting on the foremost top rolls does not tend to deform the covers of such rolls.

It is still another feature of the present invention to urge the latch of the locking device to its operative position by means of a spring that also includes two legs joined by a cross member, with such cross member being engageable in suitable notches or recesses provided in the carrier arm for releasably holding the latter in its raised, inoperative position, whereby the carrier arm can be returned to its operative position merely by exerting a downward force thereon.

The above, and other objects, features and advantages of the invention, will be apparent in the following detailed description ofan illustrative embodiment thereof which is to be read in connection with the accompanying drawings, forming a part hereof, and wherein:

FIG. 1 is a side elevational view, partly broken away and in section along the line II of FIG.'4, of a textile drawing mechanism embodying the present invention, with the carrier arm of such mechanism being shown locked in its operative or depressed position;

FIG. 2 is a view similar to that of FIG. 1, but with the device for retaining the carrier arm thereof in its operative position being unlocked;

FIG. 3 is a fragmentary view, similar to a portion of FIG. 1, but showing the carrier arm in its raised, inoperative position;

FIG. 4 is an enlarged, transverse sectional view taken along the line IV-lV of FIG. 1.

FIG. 5 is a fragmentary sectional view of a modified embodiment of the invention, the view being analogous to that of FIG. 4; and FIG. 6 is afragmentary side elevational view of the device of FIG. 5.

Referring to the drawings in detail, it will be seen that a drawing mechanism for textile spinning frames or other textile machinery which is constructed in accordance with present invention includes a carrier arm 1 having a sub stantially inverted U-shaped cross-section. The arm 1 is pivotally mounted, adjacent its back end, on a laterally extending bolt or pivot 4 which is carried by a bracket 3. The bracket or fixed support 3 has openings in its lower portion receiving a stationary support bar 7 of the associated textile machine, and a generally C-shaped gripping or clamp member 5 embraces the bar 7 within the bracket 3 and has projections 2 at one end engageable in openings of the bracket 3, while a tightening bolt 6 extends through another opening in the bracket 3 and seats against a suitable hearing at the end of the clamp member 5 remote from the projections 2 so that, by tightening a nut on the bolt 6, the clamp member 5 is made to tightly embrace the rod or bar 7 for securing the bracket 3 on the latter.

The usual twin top rolls 9, shown in broken lines in FIGS. 1 and 2 of the drawings, are individually suspended from the pivoted carrier arm 1 by suitable guide arms 8 which may be adjustable along the former, with springs (not shown) acting between the carrier arm 1 and the individual guide arms 8 to urge the top rolls 9 toward related bottom rolls 10 which are also shown in broken lines and are rotatably supported in an under frame of the drawing mechanism, for example, in the manner indicated in U.S. Letters Patent No. 2,751,632, issued June 26, 1956, to E. F. Dausch.

The top rolls 9 are pressed or weighted against the related bottom rolls 1% only when the carrier arm 1 is held or retained against upward swinging about the pivot 4 from the operative position of the carrier arm illustrated in FIG. 1. In order to retain or lock the carrier arm 1 in such operative or working position, the drawing mechanism embodying this invention has a locking device that includes latch books 12, which are best seen in FIG. 3, and which are preferably formed as integral extensions of the carrier arm 1 at the end of the latter adjacent the bracket 3. Such latch hooks 12 serve as latch keepers and define recesses 12' which open rearwardly with the carrier arm in its operative position and in which a pivoted latch is engageable, as in FIG. 1, for preventing upward movement of the carrier arm away from its operative position. The pivoted latch is preferably formed by a pair of links 16 which, at one end, are pivotally mounted on a pin carried by the bracket 3, and which, at their other ends, carry a pin 14' rotatably supporting rollers 13 (FIG. 4) which act as detent members, with such rollers 13 being movable along arcuate paths concentric with pin 15 and provided for actual engagement with the latch books 12 in order to reduce to a minimum the frictional resistance to the movement of the latch into and out of engagement with the latch hooks.

A torsion spring 17 is mounted on the pin 15 and has two legs 17 which, at their free ends, act against the pin 14 in order to urge the latch to pivot about the pin 15 in the counter-clockwise direction, as viewed in FIGS. 1, 2 and 3, thereby to tend to move the rollers 13 into the recesses 12 of the latch hooks 12. The spring 17 further includes two legs 18 which react against the back of the bracket 3 and which, at their free ends, are connected by a cross member 18 (FIG. 4) bearing against a. rounded back end on the carrier arm 1 and adapted, as in FIG. 3, to enter recesses or notches 19 formed in that rounded back end when the carrier arm is raised to the inoperative position of FIG. 3, thereby to yieldably retain the carrier arm in its inoperative position.

The drawing mechanism embodying the invention further includes a hood or cover 11 which extends over the carrier arm 1 and which constitutes an operating member for the above described locking device of the drawing mechanism. The hood or cover 11 is also of inverted U-shaped cross-section, and the sides thereof have elongated slots 11a formed therein adjacent the back end of the hood or cover to'receive the pivot 4, so that the hood 11 can swing with, or independently of, the carrier arm 1 about the pivot 4 and is also free to be longitudinally displaced with respect to the carrier arm. Further, a pin 11' (FIGS. 1 and 2) extends laterally between the sides of the hood 11 adjacent the front end of the latter and rides on the top of the carrier arm 1 to cooperate with the slots 11a in guiding the hood 11 relative to the carrier arm during longitudinal displacement of the hood. In order to hold the hood 11 against inadvertent upward swinging with respect to the carrier arm 1, the sides of the hood 11 are further provided with inwardly pressed bosses 23 adjacent the front end of the hood, such bosses being resiliently engageable below the lower edges of the carrier arm 1. A spring 22 is mounted on the pivot or bolt 4 and acts upwardly against the hood 11 to urge the latter to swing upwardly with respect to the carrier arm 1. Thus, after the hood has been forceably raised with respect to the carrier arm to the extent necessary to release the bosses 23 from resilient engagement with the carrier arm, the spring 22 is effective to complete the upward swinging of the hood away from the carrier arm.

As seen particularly in FIGS. 3 and 4, the sides of hood 11 are stamped outwardly to define downwardly and inwardly opening recesses 24 adjacent the back end of the hood, with such recesses 24 being located to receive extensions 21 at the opposite ends of the pin 14 of the latch when the carrier arm 1 is in its depressed, operative position. Further, the forward margins of the recesses 24 define rearwardly facing striking surfaces 20 which, when the hood 11 is displaced rearwardly relative to the arm 1 in the direction of the arrow A on FIG. 1, act against the extensions 21 of pin 14 to cause the latch to pivot about the pin 15 and thereby displace the rollers 13 on pin 14 from the fully locked position of FIG. 1 to the unlocked position of FIG. 2. With the latch in the unlocked position of FIG. 2, the rollers 13 are disposed at the months or openings of the recesses 12' of the latch hooks 12 so that, if the hood 11 is released and thereby permitted to return forwardly and the carrier arm 1 is pressed downwardly, the spring 17 will urge the rollers 13 back into their fully locked positions Within the recesses 12', as in FIG. 1, for immediately returning the carrier arm to its locked position. On the other hand, with the latch in its unlocked position of FIG. 2, the carrier arm 1 can be raised to its inoperative position, as shown in FIG. 3, and retained in such position by the releasable engagement of the cross member 18 of spring 17 in the notches or recesses 19 of the carrier arm.

While the latch is in its unlocked position of FIG. 2, the force of the spring 17 is transmitted, by way of the rollers 13, to the points of the latch hooks 12 in order to exert a slight force on theicarrier arm tending to urge the latter downwardly, and the individual guide arms 8 carrying the twin top rolls 9 are adjusted with respect to the carrier arm so that the twin top rolls of the foremost guide arm then rest against the related bottom rolls, while the remainder of the top rolls are raised with respect to the related bottom rolls, as shown in FIG. 2. When the individual guide arms 8 are thus adjusted with respect to the carrier arm, the latch can be unlocked, as previously described, during a prolonged stoppage of the associated textile spinning frame or other textile machine, and the twisted yarn remains gently gripped between the foremost top rolls and the related bottom rolls so that the twist of the yarn cannot extend into the drawing field. However, the relatively light pressure resulting from the action of the spring 17 when the latch is in the unlocked position of FIG. 2 does not present the danger of deformation of the covers of the foremost top rolls in engagement with the related bottom rolls.

It will be understood that the recesses 12' of the latch hooks 12 are shaped so that, when the arm 1 is in its operative or working position and the latch is in its locked position, as in FIG. 1, any force tending to raise the arm 1 is resisted by the reactions of the hooks 12 against the rollers 13 in the direction of the arrow B on FIG. 1, that is, in a substantially radial direction with respect to the pivot pin 15 of the latch, so that there is no tendency to move the latch from its locked position to its unlocked position of FIG. 2. Further, it will be apparent that the rollers 13 move upwardly, as well as toward the rear, in passing from their locked position (FIG. 1) to their unlocked position (FIG. 2), and the recesses 12' are further shaped so that, during such upward movement of rollers 13, the arm 1 can swing upwardly a slight amount from its depressed operative or working position to retain only the foremost top I'Olls in contact with the related bottom rolls, as described above. Finally, the lower edges of the recesses 12' are shaped so that, when the rollers 13 are in the unlocked position, as in FIG. 2, the force of the spring 17 will be effective to obtain the light pressure on the foremost top rolls, as previously described, but will be inefiective to return the latch to its locked position (FIG. 1) until the arm 1 is further depressed manually to its operative or working position.

In order to return the carrier arm from its raised inoperative position of FIG. 3 to its operative position of FIG. 1, it is only necessary to swing the carrier arm downwardly toward the bottom rolls 10 until the rollers 13 of the latch ride against the arcuate lower edges of the latch hooks 12 and finally are urged into their fully locked positions within the recesses 12' by the action of the spring 17. During such relocking of the latch, it is not necessary to effect any displacement of the hood or cover 11 with respect to the carrier arm 1.

If it is desired to swing the hood or cover 11 upwardly with respect to the carrier arm 1, for example, for the purpose of exposing the carrier arm 1 in effecting adjustment of the guide arms 8 from which the top rolls are suspended, such upward swinging of the hood or cover 11 can be conveniently effected while the carrier arm is forceably retained in its operative position by the locking device, thereby to facilitate the disengagement of the bosses 23 from the carrier arm.

Although the hood or cover 11 constituting an operating member for the latch is made to cooperate with the pin 14 of the latch by providing stamped recesses 24 in the hood defining striking surfaces 20 engageable with the extensions 21 of the pin 14, it is apparent that the same purpose can be achieved by substituting slots 24a for the recesses 24 as shown in FIGS. and 6, which slots extend generally normal to the direction of the longitudinal movement of hood 11 relative to arm 1 and slidably receive the extensions 21 at the opposite ends of the pin 14.

Further, although a particular embodiment of the invention has been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to that particular embodiment, and that various changes and modifications, in addition to the specific modification mentioned above, may be effected in the described and illustrated embodiment without departing from the scope or spirit of the invention, except as defined in the appended claims.

What is claimed is:

1. A textile drawing mechanism; comprising a fixed support; a top roll carrying and weighting arm pivotally mounted on said support for swinging between a lowered operative position and a raised inoperative position; a locking device for releasably retaining said arm in said operative position including keeper means on said arm, and latch means pivoted on said fixed support and moved into locking engagement with said keeper means when said arm is in said operative position; and operating means movably mounted on said support to act against said latch means for pivoting the latter out of locking engagement with said keeper means so that said arm is then free for swinging movement to said raised inoperative position.

2. In a textile drawing mechanism; the combination of a fixed support, a top roll carrying arm pivotally mounted on said support for swinging between a lowered operative position and a raised inoperative position, a locking device for releasably retaining said arm in said operative position including keep means on said arm and latch means movably mounted on said fixed support and urged into locking engagement with said keeper means when said arm is in said operative position, and operating means movably mounted on said support to act against said latch means for moving the latter out of locking engagement with said keeper means so that said arm is then free for swinging movement to said raised inoperative position.

3. In a textile drawing mechanism, the combination as in claim 2; wherein there is a spring and wherein said latch means is pivoted on said fixed support and has detent members which are movable along paths defined by an arc of a circle in response to pivoting of the latch means, and said keeper means includes latch hooks on said arm defining recesses having openings which intercept said paths when said arm is in said operative position, said latch means being urged into locking engagement by said spring acting thereagainst and tending to pivot said latch means in the direction moving said detent members into said recesses defined by the latch hooks.

4. In a textile drawing mechanism, the combination as in claim 3; wherein said detent members are in the form of rollers, and said operating means, when moved with respect to said carrier arm, displaces the rollers in the direction out of said recesses to unlocked positions at said openings of the recesses so that said arm can be immediately relocked in said operative position or raised to said inoperative position.

5. In a textile drawing mechanism, the combination as in claim 4; wherein said rollers, when in said unlocked positions, are disposed along portions of said paths which are directed downwardly with respect to said latch hooks so that said rollers are urged against said latch hooks by said spring acting on the latch means in order to lightly press said carrier arm toward said bottom rolls.

6. In a textile drawing mechanism, the combination as in claim 5; wherein said spring has a first pair of legs acting against said latch means and a second pair of legs with a cross-member therebetween, said carrier arm having a curved end within said fixed support, with said crossmember of the spring riding against said curved end and the latter having notches therein receiving said crossmember when said arm is in said raised inoperative position so that said spring also functions to releasably retain said arm in said inoperative position.

7. In a textile drawing mechanism, the combination as in claim 4; wherein said operating means has striking surfaces thereon which, upon said movement of said '7 operating means relative to said carrier arm, act against complementary surfaces of said latch means.

8. In a textile drawing mechanism, the combination as in claim 7; wherein said operating means includes a hood extending over said carrier arm and having said striking surfaces formed thereon, means mounting said hood for longitudinal movement with respect to said carrier arm, and said latch means further includes a pin rotatably supporting said rollers and having extensions defining said complementary surfaces and reaching laterally into the paths of movement of said striking surfaces with said hood. 9. In a textile drawing mechanism, the combination as in claim 8; wherein said means mounting said hood includes slots in the latter and a pivot pin carried by said fixed support and both pivotally mounting said carrier arm on the fixed support and extending into said slots of the hood so that the latter can swing with the carrier arm or independent of the latter.

10. A textile drawing mechanism comprising a fixed support; a top roll carrying movable support pivotally mounted on said fixed support for swinging between an operative position and an inoperative position; a locking device for releasably retaining said movable support in said operative position including a first locking member on one of said supports and a second locking member pivoted on the other one of said supports and moved into locking engagement with said first locking member when said movable support is in said operative position; and operating means movably mounted on said fixed support to act against said second locking member for pivoting the latter out of locking engagement with said first locking member so that said movable support is then free for swinging movement to said inoperative position.

References Cited in the file of this patent UNITED STATES PATENTS 2,644,988 Haythornthwaite et al. July 14, 1953 2,865,056 Kubler Dec. 23, 1958 2,870,488 Werth Jan. 27, 1959 2,900,675 Dausch Aug. 25, 1959 

